The purpose of this research project is to investigate the microbial conversion of aromatic amine and nitro compounds to either N-acetyl or N-glycolyl hydroxamic acids. The biochemical pathway that has been proposed as a result of previous research by the proposed principal investigator involves the interaction of the aromatic nitroso analog of any amine or nitro compound with intermediates of thiamine-catalyzed enzymic reactions. Such enzymes include the universally-distributed pyruvate decarboxylating enzymes and transketolase enzymes. The ability of a wide range of microbial ecosystems to effect these potentially dangerous conversions will be investigated. The microbial systems range from those present in cultivated soil to those present in aquatic sediments, both fresh water and marine. Most research will be concentrated initially on mixed microbial cultures in-vitro, with later studies being conducted in-situ by the use of environmental enclosures.